Mechanism for controlling gas pressures



Aug. 31 1926.

J. P. POWELL macrmmsu FOR CONTROLLING GAS PRESSURES Filed p 22, 1921' 4 Sheets-Sheet 1 m wza Gummy Aug. 31 1926. 1,597,867

J. P. POWELL MECHANISM FOR CONTROLLING GAS PRESSURE'S Filed Sept. 22, 1921 4 Sheets-Sheet 2 gwoenl'oz I mu ' 6K0: on 1 Aug. 31 1926. 1,597,867

J. P. POWELL MECHANISM FOR CONTROLLING GAS PRESSURES Filed Sept. 22, 1921 4 Sheets-Sheet 5 l .r/ h

glwvcnfoz o hw 1/0 Aug. 31 1926.

k 1,597,867 J. P. POWELL MECHANISM FOR CONTROLLING GAS PRESSURES Filed Sept. 22, l92l 4 Sheets-Sheet 4 closed a large capacity of the gas Patented Aug. 31, 1926.

JOHN PAYNE POWELL, OF SPARBOWS POINT,

MARYLAND, ASSIGNOR TO BETHLEHEM STEEL COMPANY, OF BETHLEHEM, PENNSYLVANIA, A CORPORATION OF PENN- SYLVANLA.

MECHANISM FOR CONTROLLING GAS PRESSURES.

Application filed September 22, 1921. Serial No. 502,362.

The object of the present invention is to provide apparatus to be used in combination with a plant producing gas in large quantities as a by-product, but the gas flow from which is intermittent and under a fluctuating pressure, whereby such gas flow is changed to a steady flow at sufficiently constant pressure to be supplied as fuel directly to gas engines or burners.

The -invention is particularly useful in combination with blast furnaces in which, in the manufacture of pig iron, large quantities of gas are generated which is well suited to be used as fuel for gas engines, and in other ways. The flow of gas from a blast furnace is, however, intermittent, the flow stopping whenever the blast furnace is charged, for a short period of time, and be ing interrupted for a much longer period of time, often twenty minutes, when the molten iron is being cast. These interruptions of gas flow from the blast furnace naturally cause awkward breaks in the operation of the gas engines which are using the gas as fuel, necessarily causing these engines to abruptly cease operating whenever the flow of as from the blast furnace stops.

Kccording to the present invention, novel means are provided for changing the character of the flow from the blast furnace to the point at which the gas is to be used, from an intermittent to a steady flow. The invention is susceptible of embodiment in various forms and in the form herein disgas storage tank is provided which is adapted to be filled when the gas is freely flowing from the blast furnace and to be held in reserve, and suitable devices for controlling the flow from the tank which bring it into communication with the engines or other apparatus using the gas as fuel whenever the flow from the blast .furnace has ceased, or when it pressure has fallen below a. certain pre etermined amount. The tank is such that it will insure a steady flow of gas to the engines during the entire time in which the flow from the blast furnace is interrupted so that the operation of the engines or other apparatus is continuous. Upon the resumption of the flow of storage tank is again filled and remains in -main 11.

gas from the furnace thereadiness to supply the necessary gas Whenever the flow from the blast furnace is again interrupted.

In the accompanying drawings- Figure 1 is a side elevation of the controlling apparatus and showing in section a portion of the main gas storage tank.

Figure 2 is a view similar to Fig. 1 with portions broken away to more clearly show the details of the controlling mechanism.

Figure 3 is a small scale plan view of the apparatus,

Figure 4 is a plan View of portion of the re ulating device to a larger scale, and

igure 5 is a View, partially in elevation, partially in section, and partially broken away of portions of the apparatus, showing modifications of a number of details.

Fig. 6 is a vertical sectional view of the valve shown in Figs. 1 and 2.

The pipe or conduit 10, shown in Figure 3, conducts gas from a blast furnace or other plant which intermittently produces gas as a by-product, to the main 11 through which it is conveyed to the gas engines or other apparatus using the gas as fuel, which are not shown in the drawings. Interposed between main 11 and the blast furnaces, at a suitable point along conduit 10 may be placed devices (not shown) for cleaning the gas and rendering it suitable for gas engine consumption. A large capacity gas storage tank or holder is indicated at 12, this tank being capable of holding a volume of gas suflicient to supply the engines during any usual interruption of the supply from the blast furnace.

Ordinarily the gas generated by the blast furnace flows directly to the engines through conduits 10 and 11 but when this flow stops gas flow begins from gas holder 12 to the engines, passing through the gas line 13 and Suitablecontrolling devices hereinafter to be fully explained govern'the flow of gas into and out of the gas storage tank so that it is filled when the gas pressure in main 11 is relatively high, and empties it self, or partially empties, whenever the gas pres-sure in main 11 is relatively low, due to a cessation of flow from the furnace.

At 14 and 15 respectively are illustrated two gate valves, either of which may be moved to stop the flow ofgas through conduit 13, the valve 14 being manually operable by means of a hand wheel 16 and valve being operable by any sultable power means, as, for example, a motor device con-v sisting of a piston disposed in the cylinder 18 and which is connected to the valve by a rod 19, the piston being moved by pneumatic pressure. Smallpipes 20 and 21 communicate with the interior of c linder 18 at its ends respectively, and wit opposite ports of a four-way air valve 22 as may be seen from Fig. 6. Pipes 20 and 21 serve alternately as air inlet and air outlet conduits for the cylinder. Pipe 23 connects a third port of valve 22 with a. suitable source of air under pressure and a fourth pipe 24 leads from the fourth port of valve 22 to a relief valve 25. A valve lever 26, which is connected to a rotatable valve plug 26' shown in Fig. 6, is adapted to be automatically operated to turn the valve and to brlng either end of cylinder 18 into communication with pipe 23 and simultaneously to bring the other end of the cylinder into communication with the relief valve 25. The piston 17 and its associated valve 15 may, therefore, be moved in either direction to open or close the conduit 13, depending upon the manipulation of valve 22.

One end of lever 26 is provided with a laterally projecting pin 27 which is received within a slot 28 formed in a vertically disposed bar 29 pivotally secured at its upper and lower ends to rockers 30 and 31 respectively. The ends of rockers 30 and 31 lying opposite bar 29 are connected b a second vertically disposed bar 32, the our associated members 29, 30, 31 and 32 forming a parallel linkage construction. Rocker 31 is pivotally supported upon a stand 33 resting upon the foundation and rocker 30 is rigidly supported upon a horizontal shaft 34 mounted in bearings 35 supported upon a channel bar 36. This shaft has also rigidly supported thereon a laterally extending arm 37 having a weight 38 suspended from its outer end, and'segmental members 39 and 40 extending in opposite directions and the curved outer ends of which are grooved to receive cords or ropes 41 and 42 respectively.

Cord 41 has its lower end secured at 43 to the lower corner of segmental member 39 and its upper end secured to the top of a tripod or bracket 44, mounted upon the movable bell or element 45 of a gasomete-r G. The upper end of cord 42 is secured at 46 to the upper corner of segmental member 40 and to its lower end is secured a. heavy weight 47 which substantially balances the gasometer bell 45. The weight 38 alone opposes the upward movement of bell 45 due to increase of gas pressure and it will be observed that the weight 47 has a constant lever arm and therefore exerts a constant torque on shaft 34 while weight 38 has a lever arm which increases as shaft 34 is rotated in a counter clockwise direction by the rise of bell 45.

The lever arm of any force which may be exerted upon segment 39 due to upward movement of member 45 of the gasometer is also constant.

Gasometer G is connected by means of a conduit 48 with athree-way gas valve 49 .and this valve is connected by pipes 50 and 51. to the gas main 11 and gas line 13 re-. spectively, the pipe 51 communicating with line 13 at a point between valve 15 and the gas storage tank 12. Valve 49 has an operating lever 52 also provided with a laterally projecting pin 53 which is received within a second slot 54 of rod 29. By shifting the angular position of lever 52 the valve may be changed to bring the gasometer into communication with either pipe 13 or main 11.

Secured to the end of lever 26 on the opposite side of valve 22 from pin 27 is a weight 56 which rests, when the lever is in the position in which it is illustrated in Figure 2, on a stationary bracket 57, rigidly supported in any suitable manner. Also secured to this end of lever 26 is one end of a rope or cable 58 which passes over suitable anti-friction pulleys and the opposite end of which is fastened to the bell 59 of the small gasometer S Gasometer S communicates through pipe 60 with the conduit 50v and acts, therefore, in accordance with the pressure existing in the gas main 11 at all times.

Likewise secured to the end of lever 26- is one end of cable 61 which passes over suitable supporting pulleys and has a vertical portion adjacent the gas holder 12 to the lower end of which is secured a weight 62. A weight 63 is hung from this cable by means of a pulley 64. Cable 61 is also provided with an enlargement or lug 65 constituting an abutment against which a bracket 66 is secured to the upper member of the telescoping gas holder.

The operation of the mechanism so far described is as follows: The various moving parts illustrated in Figures 1 and 2 are in the positions which they would occupy in case the gas pressure in the main 11 has just fallen below the lower limit desired, allowing the gasometer bell 45 to descend, effecting the upward movement of bar 29 and thereby moving air valve 22 toopen gate valve 15 and operating valve 49 so as to establish communication between the gasometer G and gas line 13 on the holder side of the gate valve, that is, through pipe 51. The demand of the engines for gaseous fuel is greater than the blast furnace supply, and gases therefore flow from the storage tank 12 through conduit or gas line 13 to main 1] and thence to the engines. The parts will remain in this position until the pres sure in the gas main 11 has again risen or until the storage tank 12 is practically empty.

Vhen the gas again begins to flow from the blast furnace, the pressure in mam 11 will immediately rise, causing the storage tank to fill, and the gasometer bell to commence to rise. Bar 29 immediately begins to descend, the top of slot 28 approaches pin 27, and the top of slot 54 approaches pin 53. This movement will continue until the top of slot 28 contacts with pin 27 and at this position the upward movement of the gasometer bell is temporarily halted, inasmuch as the total upward force of the gas beneath the same will not be sufficient to raise weights 56- and 63 both of which act to keep lever 26 in the position in which it is shown in Figure 2. The weight 63 remains suspended, as the weight 62 is more than half as heavy and it is thereby enabled to anchor the end of cable 61 against upward movement. Although the upward movement of the gasometer bell 45 is halted, the pause is temporary only in that the storage tank 12 is constantly filling and ultimately bracket 66 contacts with lug and cable 61 is relieved of the weight 62 allowing, as the gas holder further inflates, the weight 63 to descend and rest on the foundation. WVhen this has taken place gasometer bell 45 may continue its upward movement, being able to over-- come without difficulty the action of weight 56. In this upward movement of course the gasometer bell must overcome the constantly increasing resistance offered by weight 38 the lever arm of which increases as the bell rises. It will be seen that if a constantly increasing resistance were not offered to the upward movement of hell 45, it would move upwardly suddenly at the instant the gas pressure was able'to overcome the resistance of weight 56. The use of weight 38 and its novel means of support therefore insures the gradual movement of the bell.

After the bell has risen a predetermined amount, as determined by the length of slots 28 and 54, valve levers 26and 52 are operated and the positions of the air and gas valves reversed so that gate valve 15 is closed and the gasometer G brought into communication with the main 11 through pipe 50. Gate valve 15 will remain closed until the pressure in main 11 has fallen to such an extent that gasometer bell 45 has fallen and caused the movement of valve lever 26, it being understood that the gas holder or storage tank 12 is full and the weight 63 therefore resting upon the ground or foundation and not opposing movement of the valve lever.

Under some conditions, the fiow of gas from the blast furnace may be interrupted for an unusual length of time so that the contents of the holder 12 are exhausted. In-

asmuch as the gas engines would continue to operate even when the gas fuel is supplied at less than atmospheric pressure, it is possible for them to actually create a depression or partial vacuum in the holder 12 which, were it sufficiently great, might cause the collapse of the storage tank. To avoid all danger of such an occurrence, the gasometer S is provided, the bell 59 of which rises and falls in accordance with the pressure existing in main 11, as previously explained. The area of hell 59 is such that the downward force realized on the same due to the difference in pressure existing within and without the system will be sufficient to raise both weights 56 and 63 to effect the closure of the gate valve 15, when the pressure in the main 11 has fallen below the predetermined. minimum, This force is of course numerically equal to the horizontal projection of the bell expressed in units of area multiplied by the difference between the atmospheric pressure existing and the pressure existing within the bell plus the weight of said bell. \Vhenever this force, which is downward, overcomes the sum of the downward forces of weights 56 and 63, the main gate valve will close and will not reopen until the pressure in main 11 has again risen above the minimum desired.

It is possible to dispense with the use of cable 61 and weights 32 and 63 so that the valve is opened and closed strictly in accordance with the movements of hell 45 and small gasometer bell 59. It is found, however, that the gas flow from the blast furnace is irregular and that the pressure 1n main 11 varies considerably from time to time. Without cable 61 and its associated parts, it is possible that the gasometer bell or element 45 might be rapidly raised by sudden but temporary increase of pressure and the gate valve 15 closed before the gas storage tank 12 was full. Cable 61 and its associated mechanism therefore comprises a means which in turn controls the gate valve operating means, rendering this last mentioned means inoperative except when the holder is full.

Gas valve 49, as before explained, brings.

the gasometer G into communication with the holder when the gasometer bell 45 falls, and into communication with the gas main 11 when the gasometer bell 45 rises. It constitutes a means, therefore, for insuring that the gasometer G and the gate valve are admotive fluid supplied thereto under the conjacent the storage tank and at some distance away from the main 11. The pressure existing in the holder or storage tank and main 11 may, under such circumstances, vary considerably.

'In' Figure 5 mechanism is illustrated which may be substituted for cable 61 and its associated weights illustrated in Figures 1 or 2. In this modification a vertically reciprocable rod is positioned adjacent the tank 12, this rod having a lug 71 adjustably secured thereto and lying in the pathway of the bracket 72 secured to the upper section of the storage tank. The lower end of this red is pivotally connected to a lever 73 for operating an air valve 74 which controls the passage of air under pressure from a suitable source to the bottom of the cylinder 75. A piston 76 is vertically reciprocable within the cylinder and has an upwardly extending piston rod 77 upon the upper end of which may be mounted a weight 78. Rod 77 is connected by a cable 79 to lever 26 which controls air valve 22 as in Figures 1 and 2.

Valve 22 is operated in the manner previousl I described, by means of the gasometers and S, but in this instance the gasometer bell 45 is powerless to operate lever 26 until piston 7 6 has been raised, relieving lever 26 of the weight of the piston, and the additional weight 78 mounted thereon. In other words, the valve 15 cannot be closed until the gas storage tank 12 has been filled. A small port 80 g-controlled by a needle valve 81 allows air to leak from the cylinder after valve 74 has been closed to allow the piston 7 6 to descend.

The apparatus just described will be preferred to the form illustrated in Figure 2 in which cable 61 is employed in cases where the cable must necessarily be exposed and may become rusted and stiff in operation due to the action of the elements.

From the foregoing, it will be apparent that I have devised, in connection with an 'expansible gas holder and a gas producer connected to a mam, the holder, being con nected by a conduit having a valve, automatic controlling apparatus to open and to close the valve. The automatic controlling apparatus closes the valve in response to the attainment of a predetermined gas pressure and a predetermined volume in the holder as well as in response to a predetermined low-pressure condition in the main and such apparatus opens the valve in response to a predetermined low-pressure condition in the main so as to supply the latter with gas from the holder. The automatic controlling apparatus includes essentially an operating mechanism or motor device 18 for opening and closing the valve 15, the operating mechanism or motor device 18 having energy or trol of suitable controlling mechanism. The controlling mechanism includes a valve or controlling device 22, which is operated, through the intermediary of motion-transmitting means, by apressure-responsive device or gasometer G in order to open and close the valve 15. The controllin mechanism also includes means, already escribed, for preventing closure of the valve 15 imtil'a predetermined volume is attained in the holder. The motion-transmitting means preferably takes the form of the parallel motion mechanism already specifically described and which includes a bar or memher 29 for operatim the valves 22 and 49. The controlling medhanism furthermore includes a gasometer S for the purpose of operating the valve or controlling device 22 so as to cause the motor device or operating mechanism 18 to close the valve 15 in case such a low-pressure condition should exist in the main as would be likely to resuit in injury to the holder.

It will be apparent to those skilled in the no art that other details of the invention may be modified and that it is not limited in scope to the particular design and arrangement of parts described and illustrated.

Having thus described my invention what is claimed as new and desired to be secured by Letters Patent is:

1. In apparatus of the character described, the combination of a gas main; a gas holder; a conduit for connecting the holder to I the main; a valve in the conduit; motor means for opening and closing the valve; and controlling mechanism for the motor means Including means responsive to'a decline in gas pressure in the main to render the motor means effective to open the valve and responsive to an increase in holder and main pressure to render the motor means effective to close the valve.

2. In apparatus of the character described, the combination of a gas main; an expansiblegas holder; a conduit for connecting the holder to the main; a valve in the conduit; motor means for opening and closing the valve; controlling mechanism for the motor means including means responsive to a de cline in gas pressure in the main to render the motor means effective to open the valve and responsive to an increase in holder and main pressure to render the motor means effective to close the valve, and means for preventing the pressure-responsive means from rendering the motor means effective to close the valve until the expansible gas holder attains a predetermined volume.

3. In apparatus of the character described, the combination of a gas main; a gasholder; a conduit for connecting the holder to the main; a valve in the conduit; operating mechanism operated by air for opening and 130 closing the valve; controlling mechanism for the operating mechanism including a device for controlling the supply of air to the operating mechanism, a gasometer having a movable element, means for transmitting motion from the movable element of the gasometer to the device, conduits for connecting the gasometer either to the main orito the holder, valve means effective to open either of thelast-n'amed conduits and to close the other thereof, and means for operating said valve means from the motiontransmitting means.

4. In apparatus of the class described, the combination of a gas main; a gas holder; a conduit for connecting the holder to the main; a valve in the conduit; mechanism 'for opening and for closing said valve including a gasometer having an element mov able in one direction in response to increasing pressure of gas in the gasometer and movable in the other direction in response to decreasing pressure of gas in the gasometer, connecting means between the movable element of the gasometer and said valve, whereby the latter is closed when said movable element has moved a predetermined amount in one direction, in responseto increasing gasometer gas pressure and is opened when the movable element has moved a predetermined amount in the other direction in response to decreasing gasometer gas pressure, conduit means for connecting the gasometer to the main, and means for applying increasing resistance to movement of said movable element in response to increasing gas pressure in the gasometer.

5. In apparatus of the class described, the combination of a gas main; a gas holder; a conduit for connecting the holder to the main; a valve in the conduit; mechanism for opening and for closing said valve including a gasometer having an element movable in one direction in response to increasing pressure of gas in the gasometer and movable in the other direction in response to decreasing pressure of gas in the gasometer, connecting means between the movable element of the gasometer and said valve, whereby the latter is closed when the movable element has moved a predetermined amount in one direction in response to increasing gas- 'ometer gas pressure and is opened when the movable element has moved a predetermined amount in the other direction in response to decreasing gasometer gas pressure, conduit means for connecting the gasometer to the main, said connecting means including a rock shaft, and a weighted arm connected to the rock shaft and inclined downwardly when said movable element is in a low-pressure position, whereby said arm opposes increasmg resistance to movement of the movable element in response to increasing gas pressure in the gasometer.

6. In apparatus of the class described, the combination of a gas main; an expansible volume gas holder; a conduit for connecting the holder to the main; a valve in the conduit; mechanism for opening and for closing said valve including a gasometer having an element movable in one direction in response to increasing pressure of gas in the gasometer and movable in the other direction in response to decreasing pressure of gas in the gasometer, connecting means between the movable element of the gasometer and said valve, whereby the latter is closed when the movable element has moved a predetcrmlned .ing the holder to the main; a valve in the conduit; fluid-pressure-operated operatin mechanism for opening and for closing said valve; controlling mechanism for the op erating mechanism including valve means to control the admission and exhaust of motive fluid to the operating mechanism to cause the latter to open or to close the conduit valve, a gasometer including a movable element, means for transmitting motion from the movable element of the gasometer to said valve means to operate the latter, conduits for connecting the gasometer either to the main or to the first-named conduit between the valve of the latter and the holder, valve means for the last-named conduits and'effective to open either of the latter conduits and to close the other, means for operating the last-named valve means from the motiontransmitting means, and means for preventing said motion-transmitting means from operating the motive-fluid valve means to render the operating mechanism efi'ective to close the conduit valve until the expansible volume holder attains a predetermined volume.

8. In apparatus of the class described, the combination of a gas main; a gas holder; a conduit for connecting the holder to the main; a valve in the conduit; a motor device for opening and for closing said valve; controlling mechanism for the motor device including motive-fluid valve means to control the admission and exhaust of motive fluid to the motor device to cause the latter to open or to close the conduit valve, a gasometer including a movable element, means either of the latter conduits and to close the other, means for operating the last-named valve means from the motion-transmitting.

means, and means responsive to a predetermined lowressure condition in the main to actuate t e motive-fluid valve to operate the motor device to close said conduit valve.

9. In apparatus of the class described,the combination of a gas main, a gas holder, a conduit connecting the main and holder, pressure controlled means for automatically closing the conduit, means for rendering said first mentioned means inoperative except when the holder is full including a piston connected to said first mentioned means, a cylinder for the piston, a pipe for leading fluid under pressure to said cylinder, a valve controlling the passage of fluid through said pipe, and a member for operating said valve in accordance with the volume of holder.

10. In apparatus of the character described, the combination of a gas main, a variable volume storage tank having com munication with the main, a valve between the storage tank and the main and adapted to establish and to interrupt communication therebetween, a gasometer including a movable'bell, conduits adapted to connect the gasometer with the storage tank or with the main, a valve for controlling connection of the gasometer with either of the conduits, means for counterbalancing the bell, mechanism responsive to upward movement of the bell to close the first-named valve and to 0perate the second-named valve to connect the gasometer and the main, means responsive to the attainment of a predetermined volume by the storage tank to render said mechanism effective, and means for applying increasing resistance to the upward movement of said bell.

In testimony whereof I hereunto atfix my signature.

JOHN PAYNE POWELL.

gas in the 

